The short answer is yes you can convert the device, but it will not be supported. If you call Dell Technical Support, they will ask you to reflash the device with ThinOS.
To flash (install Windows IoT 10) the device you will do the following:
Download the Windows 10 IoT image https://dl.dell.com/FOLDER08703114M/1/WIE10_LTSC_2019_UNIFIED_MR2_June2022.exe
Using 7-Zip, extract the image, when extracted browse the folders and locate the commandxml.xml file
An important step here, using Notepad search and replace FFFFFFFF with 000000FF and save the file.
On a separate PC (not a thin client) Download and install the Dell Wyse USB Tool: https://dl.dell.com/FOLDER08327725M/1/Dell_Wyse_USB_Imaging_Tool_v3.5.0.exe
Run the application with a blank USB key (32GB recommended)
You will need to prepare the key, use the pull image option, make sure to select 64-bit, and update the key.
When completed, restart the application
Now, select Push Image option, using the Plus sign browse the folder of the extracted image, select the *.rsp file.
Now select Update, this will prepare and copy the image to the key.
Boot the device, enter into BIOS and change the BIOS option to allow for USB boot.
Restart the device and enter boot menu, select the USB Key and your will follow the prompts from there.
Hope this helps